An integrated circuit (IC) die is often fabricated into a processor for various tasks. The solder that is used to complete electronic connections between the IC die and the outside world often requires a significant amount of thermal budget to get the solder to reflow and to adhere properly for useful connections.
One problem that must be addressed in the connection of various different types of materials (i.e., microelectronic devices, substrates, heat slugs, etc.) is the coefficient of thermal expansion (CTE) for each material. The CTE is a measurement of the expansion and contraction of each material during heating and cooling cycles, respectively. These heating and cooling cycles occur during the operation of a microelectronic device and during power up and power down of the microelectronic device. Various materials can be selected to modify the problems with CTE mismatch, but processing temperatures are often higher than desirable.